THE DISTRIBUTION PATTERN OF CARBON-14 ASSIMILATED BY A SINGLE LEAF IN TOBACCO PLANT

When ¹⁴CO₂ was administered to a fully expanded leaf (12th leaf)of tobacco plant at the stage just before flower budding, about30% of ¹⁴C assimilated was translocated to other organs after3 hours. After 21 hours, 20{small tilde}30% of the radioactivitywas translocated to the roots, about 20% to upper stem, 10%to lower stem, and 10% to the 17th leaf located directly abovethe 12th leaf. The amount of ¹⁴C translocated to other leaveswas small after 31 hours. When ¹⁴CO₂ was applied to the 17th leaf, radioactivity in otherorgans was negligible. Judging from the time course of ¹⁴C-incorporation into organicsubstances, it was inferred that sucrose imported into the rootsfrom the 12th leaf was converted into compounds of cationicfraction and sugar esters. ¹⁴C imported into the 17th leaf was mostly incorporated into80% ethanol-soluble fraction, especially into sucrose. On theother hand, ¹⁴C fixed photosynthetically by the 17th leaf wasmostly recovered in starch and protein fraction after 8 hoursof ¹⁴CO₂ assimilation. ¹A part of this paper was presented at the Japanese Societyof Plant Physiologists, in April, 1965. ²Present address: Central Research Institute, Japan MonopolyCorporation, Shinagawa-ku, Tokyo.     

Rhythms in respiratory metabolism of Lemna gibba G3 under continuous illumination

Changes in chemical constituents and respiratory metabolismof a long-day duck-weed, Lemna gibba G₃ exposed to continuousillumination after short-day cultivation were investigated.The dry weight to fresh weight ratio was constant during thefirst 72 hr of continuous illumination. pH of the crude extractwas constant at 6.6, but pH of the culture medium was raisedwith the Lemna growth. Titratable acidity decreased after about44 hr, whereas malic acid content increased in 18 hr. Therewere no significant changes in total reducing sugar and pentose.Total protein content and lipid showed rhythmical changes withcycles of 48 hr. O₂-Uptake gave a damped oscillation with cycles of 24 hr. Itwas low in the first half day and high in the second half. ¹⁴CO₂-Outputfrom glucose-l-¹⁴C showed a similar damped oscillation. ¹⁴CO₂-Outputfrom glucose-2-14^C or glucose-6-₁₄C was almost constant. TheC₆/C₂ ratio, then, showed damped oscillation in the reverseway to O₂- uptake between 0.3–0.5, and the C₈/C₂ ratiowas constant at 0.9. Accordingly, the diurnal rhythm of O₂-uptakewas thought to be brought about by variation in activity ofthe pentose-phosphate pathway. Reproduction of glucose-6-phosphateby the pentose-phosphate pathway was presumably limited in amount. Glyceraldehyde-3-phosphate dehydrogenase activity varied diurnally.The activities of NADP-linked and NAD-linked enzymes increasedand decreased, respectively, in the first half day. Variationsin these enzymatic activities are discussed in correlation withrhythmical changes in O₂-uptake and in the C₆/C₁ ratio. Acidphosphatase activity also followed a diurnal variation. No activitiesof alcohol and formic dehydrogenases were found. The activitiesof NADP glucose-6-phosphate dehydrogenase, 6-phosphogluconatedehydrogenase, pyruvic kinase and NADP isocitric dehydrogenasewere high, but showed no rhythmical variation. ¹Presented at the Annual Meeting of the Botanical Society ofJapan, 1966 (Proceedings, p. 46). Adapted from a thesis submittedby the first author (H. M.) in 1967 to the Biological Institute,Nagoya University in partial fulfillment of the requirementsfor the degree of M. S. (Received May 8, 1969; )     

Palynotaxonomy of Brazilian species of Polygala subgenus Hebeclada

This study used pollen morphology to address taxonomic controversies related to several species belonging to subgenus Hebeclada of the genus Polygala (Polygalaceae). According to the last traditionally accepted revision of this subgenus, it comprises 40 species. Nevertheless, a recent taxonomic treatment applying more comprehensive criteria reduced this number to only nine species. Our work focused on 15 traditionally accepted species that occur in Brazil, fourteen of which have been considered as only six species in this recent taxonomic study. Pollen grains from floral buds at pre‐anthesis were collected from herbarium specimens and analysed using both visible light and scanning electron microscopy. Most of the traditionally accepted species were distinguished by different combinations of several pollen‐related features, in particular colpi number (13 or 15), pollen size and shape, and endoaperture type (endocingulate or not) and arrangement (parallel or sinuous). The species accepted in the recent taxonomic treatment could not be discriminated by pollen characters. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 609–619.     

Analysis of lichen substances including triterpenoids by high performance liquid chromatography with a differential refractive index detector and a photodiode array detector

A new method for analysis of lichen triterpenoids was established using high performance liquid chromatography with the combination of a differential refractive index detector (RID) and a photodiode array detector (PDA). It is proved that this method was convenient to detect and identify aromatic and aliphatic lichen substances; it enabled quantitative analysis of substances having no or less absorption of ultraviolet rays such as triterpenoids. In addition, they can be measured in high accuracy compared with the TLC method.     

Stem distribution and clonal structure of Chamaecyparis pisifera growing in an old-growth beech-conifer forest

To elucidate sapling patch formation and the mode of regeneration occurring in Chamaecyparis pisifera, we investigated stem distribution and clonal structure of this species in an old-growth beech-conifer forest in central Japan. The study was carried out in a 1-ha plot using small and large sapling (d.b.h.<5cm, 0.5mheight<2 m and d.b.h.<5cm, height2m, respectively) and adult (d.b.h.5cm) stems of Chamaecyparis pisifera. The numbers of small and large sapling stems were 677 and 149 in the plot, respectively, and they were strongly aggregated. Adult stems occurred at much lower density (90 stems in the plot) and were weakly clustered. Fifty multilocus genotypes at nine allozyme loci were detected among sampled stems. Small and large sapling stems with identical genotypes showed aggregated distribution, while some neighboring adult stems had the same genotypes. Spatial autocorrelation of alleles in small and large sapling stems revealed a strongly positive association among stems within a distance of 10m; but a negative association as distance increased. In adult stems, a strongly positive value was found only in the shortest distance class. These results indicate that clonal growth by layering occurred at the sapling stage and contributed to patch formation. Our results also suggest that the clonal growth by layering is ecologically significant throughout the life history of Chamaecyparis pisifera, particularly as an important strategy for the sapling establishment in the early stage of regeneration process.